Island



(No Mo l) N. G. HERRES PF' STEAM BOILER.

Patented J e 14 v UNiTEpf STATES PATENT OFFICE.

NATHANIEL GREENE HERRESHQFF, o j smsroL, RHODE ISLAND,ASSIGNOR TO THE HERRESHOFFI MANUFACTURING COMPANY, oF-sA E PLACE.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 605,786, dated when, 1898. Original application filed September 28,1397, Serial No. 653,2881 l Divided eta thisapplicatioii filed January 11,1898. Serial v No. 666,307. @(No model.)

T all whom it m/my concerni- Be it known that I, NATHANIEL GREENE HERRESHOFE, a citizen of the United States, residing at Bristol, in the county of Bristol and State of Rhode Island, have inventedfa' certain new and useful Improvement in Steam Boilers, of which the following is a specification. i

My improvementis intended more espero cially for use in what is known as the Du Temple form of boiler, in which the fire-surface is presented mainly by tubes more or less bent and connecting three horizontal cylf I. inders, the middle one being the high'est,"the' [5 tubes, properly bent, extending therefrom to the lower cylinders on each side, respectively.

I have devised important improvements in the details. 7 I

Myimprovements are intended more espezo cially for steam vessels of moderate size, as

yachts and torpedo-boats,and I willdescribe the invention as thus applied; but it may be of service in many other situations. A I provide bevel-corner bricks in the front 2 5 and back walls of the furnace, which conveniently and efficiently allow the admissionof heated air in small streams above the sur-' face of the burning fuel. I provide also, for reliably locking together the several firebrieks and the metallic casing and also for more efficiently preventing any backflow of the gases from the boiler into the fire-room in case of the bursting of a tube or other similar accident. 1 L

5 The accompanyingdrawings form a part of this specification and represent what I con-' "B arethe two lower shells, one on each side, respectively, 0 C the bent tubes arranged along the sides of the furnace, and ,O'the large inclined tubes at the rear connecting the shells, all in the style long and favorably known in the D11 Temple boiler.

(Pare baffle plates extending down from thecentral shell a considerable distance just exterior to the tubes;

- D is the grate, extending across so far below the side shells B that its edges are directly under them.

' EYE are thefire-brick sides of the furnace,

and FF the" fire-brick walls at the front and rear-of the furnace.

Ffi'is' the inclined portion of the casing above, which conducts the products of comiblIStiOIl to the stack G. [H is the thin shell of the ash-pit, and I I I are the movable'pans therein. The sides of the ash-pit areof two thicknesses and inclined, asshown.

The walls F are formed each with'an iron shell F' on'the outer face and a wall of firebrick on theinner face, with a continuous space between, inaintainedby giving a proper length 'to, the holding-bolts. The lower portion of this space is in free communication with the ash pin; The bricks in the wall are beveled,'s0 that theat e at the corner junc- 8o tions triangular passages f, leading quite through the brick portion of the wall from the connected air-space' to' the interior of the furnace. When, as usual, a partial vacuum obtains above the fire-bed in the furnace,

streams of fresh airwill be drawn in through the small passages thus provided; If a blower is employed and a pressure above that of the atmosphere obtains in the ash-pit, the same is felt in the connected space between theoo brick wall and the continuous outer shell of =metal F, so that still more fresh air under pressure will enter through the small passages and supply oxygen properly distributed to burn the gases in the furnace.

F are the holding-bolts. They lie with shell, adjusted and secured. by nuts F F. The bricks may be molded or pressed with the proper recesses for the heads of these bolts in the mid-thickness and with the proper channels extending from the head-recess through the portion of the thickness of the brick required to reach the outer face; but in case the bricks are not so formed it is but little labor to out recesses by ordinary tools. In case the fire-bricks are cemented together with fire-clay the bolts are inserted while the material is plastic, and they may be thus tightly matched. Ordinarily no such mortar is required. My invention in the absence thereof allows a slight yielding of the wall, which is an advantage on shipboard or in any case where the boiler or its adjacent parts may be required to spring or yield. The metal shell F may be of sheet-iron or low steel, giving great strength with but little thickness and aifording effieient and slightlyelastic support to the brick portion of the wall.

M is the feed-pipe, receiving water in the ordinary manner from the pump (not shown) and delivering it in the lower portion of the upper drum. M is an auxiliary feed-pipe correspondingly located on the opposite side.

My boiler is adapted to serve either with natural draft or with a blower. The efficiency of this style of boiler allows the heat generated in a large grate to be utilized in the space immediately over it. This is a great advantage in swift steam vessels; but there is increased liability of the gases to be driven downward through the fire and out through the ash-pit in emergencies. 1 provide at the front of the ash-pit a light selfaeting damper Q, turning on a light axis at q and of arched form. lVhile the draft is flowing properly this light arched damper is held up to the horizontal position, being received in a recess provided between the axis q and the grate, the current of air beneath keeping it well open, as shown in dotted lines in Fig. 1, so that it offers no appreciable 0bstruction to the air. lVhen through a sudden failure of any part, as the bursting of a I do not in this patent claim the broad grate in a plane below the side drums and extending outward under the same,because such is made the subject-matter of a separate application for patent filed September 28, 1897, Serial No. 653,287. Neither do I claim in this patent the provisions for conducting away the steam in a dry condition, such being made the subject of a separate application for patent filed September 2S,1807,Serial No. 653,288, of which this present is a division.

I claim as my invention- 1. In a steam-boiler having a central drum A and lower side drums B with connections 0 O, the front and rear walls F containing fire-bricks having their corners beveled, in combination with an exterior shell of metal F and with a continuous intermediate airspace in free communication with the ashpit, arranged to serve substantially as herein specified.

2. In a steam-boiler having a central drum A and lower side drums B, with connections 0 O, the front and rear walls F containing fire-bricks provided with recesses f in their mid-thickness, in combination with an exterior shell F of metal held at a little distance outside of such bricks, bolts F having their heads and the adjacent portions of the shanks recessed into the bricks of the wall, and their opposite ends adj ustably secured in the metallic shell, and adjusting-nuts F F all arranged to serve substantially as herein specified.

3. In a steam-boiler furnace a brick wall F havingbricks formed and matched together so as to provide air-spaces f at the angles, a continuous metallic shell F exterior to such wall, and standing at a suffieient distance therefrom to provide an intermediate airspace connecting the several apertures in the brick wall with the ash-pit, a series of holding-bolts F having their heads and adjacent portions engaged with the brick wall and their opposite ends engaged with the metallic shell, and adjusting-nuts F F", all combined and arranged to serve substantially as herein specified.

4. In a steam-boilerasl1-pit, the-damper Q, of arched form adapted to automatically open by the incoming air and assume a horizontal position within a recess provided, and close and resist archwise any back pressure of the gases, combined and arranged to serve substantially as herein specified.

NATHANIEL GREENE lllllllillSllOlF.

\Vitnesses:

K. K. II. DE \VOLF, (J. W. YOUNG. 

